Differential Diagnosis for Testicular Pain and Swelling
Single Most Likely Diagnosis
- Epididymitis: This is the most likely diagnosis given the patient's symptoms of testicular pain and swelling, recent history of dysuria and urethral discharge, and the presence of numerous neutrophils on the Gram stain. Epididymitis is often caused by a bacterial infection, commonly Chlamydia or Gonorrhea, which can ascend from the urethra to the epididymis.
Other Likely Diagnoses
- Orchitis: Inflammation of the testis itself, which can occur alongside epididymitis (epididymo-orchitis) and is also often caused by bacterial or viral infections.
- Urethritis: Given the patient's symptoms of dysuria and urethral discharge, urethritis is a likely diagnosis, potentially caused by the same pathogens suspected in epididymitis.
Do Not Miss Diagnoses
- Testicular Torsion: Although less likely given the gradual onset of pain and the presence of infectious symptoms, testicular torsion is a medical emergency that requires immediate attention. It presents with sudden, severe testicular pain and can lead to testicular necrosis if not promptly treated.
- Appendicitis: Although the pain is localized to the testes, appendicitis can sometimes present with referred pain to the groin or testicles, especially if the appendix is retrocecal. It's a critical diagnosis not to miss due to the risk of perforation.
Rare Diagnoses
- Henoch-Schönlein Purpura (HSP): A systemic vasculitis that can cause testicular pain and swelling, though it is more commonly associated with purpura, arthritis, and abdominal pain.
- Mumps Orchitis: A viral infection that can cause orchitis, typically in non-immunized individuals. It's less likely given the patient's recent symptoms of urethral discharge and dysuria, which suggest a bacterial etiology.